Position and movement reproducing apparatus



NOV. 6, 1951 R [RELAND 2,574,104

POSITION AND MOVEMENT REPRODUCING APPARATUS Filed July 1, 1946 5 Sheets-Sheet l Nov. 6, 1951 R. P. IRELAND 2,574,104

POSITION AND MOVEMENT REPRODUCING APPARATUS Filed July 1, 1946 3 Sheets-Sheet 2 Nov. 6, 1951 R. P. IRELAND 2,574,104

POSITION AND MOVEMENT REPRODUCING APPARATUS Filed July 1, 1946 3 Sheec s-Sheet 3 g -?L k I26 x26 /2 l I27 150, 9 w 933 0.0 o m, ot

Patented Nov. 6, 1951 POSITION AND MOVEMENT REPRODUCING APPARATUS Richard P. Ireland, Chicago, 111., assignor, by mesnc assignments, to Ampro Corporation, Chicago, 1ll., a corporation of Illinois Application July 1, 1946, Serial No. 680,597

9 Claims.

The present invention relates to systems for reproducing programs of movements between accurately defined positions, especially to systems whereby a, record may be made on a body of recording material of signals corresponding both to positions and to rates and degrees of move ments between such positions, and whereby subsequently the signals may be reproduced from the record body and used to control operation of a motor repeater device in such manner as to produce the intended position and motion program.

The primary object of the invention is the provision of such a system, of novel arrangement, capable of highly satisfactory production or reproduction of a predetermined motion program accurately controlled as to positions, and rates and degrees of movements between such positions, and of very simple but highly eifective arrangement.

Other objects and advantages will become ap parent to those skilled in the art upon reference to the accompanying specification, claims, and drawings in which Fig. l is a diagrammatic illustration of a transmitter and recorder unit of a preferred type forming an element of the system of the invention.

Fig. 2 is a schematic diagram of a repeater station comprising a device for reproducing a signal from a record, as that produced by the recorder and transmitter of Fig. 1, and a receiver motor for operation by a signal so reproduced.

Fig. 3 is a schematic illustration of a modified form of transmitter;

Fig. 4 is a schematic illustration of a further modified form of transmitter;

Fig. 5 is a schematic illustration of a servo mechanism;

Fig. 6 is a partial wiring diagram of a portion of the voltage amplifier utilized in Fig. 5;

Fig. 7 is a schematic wiring diagram of the power amplifier utilized in Fig. 5.

Referring now to Figs. 1 and 2 together, a transmitter is generally designated at III and a receiver at ll. The transmitter I includes a primary winding consisting of windings l2, l3 and H connected in delta and to a source of three phase alternating voltage. The primary windings provide a three phase rotating field. The transmitter also includes a single phase secondary winding l6 inductively coupled to the primary winding. Either the primary winding or the second winding may be carried by a rotor I! so that relative motion between the primary and secondary windings is provided. The rotor I! may be rotated through a suitable mechanical connection l8 by a device [9 the movement and position of which is to be reproduced.

The three phase primary winding induces or generates a single phase alternating voltage in the secondary winding I6 and because of the rotating field produced by the primary winding the phase displacement of the single phase alterhating voltage in the secondary winding IE depends directiy upon the angular position of the secondary winding it with respect to the primary winding. In other words, for every position there is a corresponding phase displacement.

Upon movement of the secondary winding i6 with respect to the primary winding because of shifting from one phase displacement to another, the frequency of the alternating voltage generated in the secondary winding I6 is caused to change and the change in frequency is directly proportional to the rate of movement of the secondary winding 16 with respect to the primary winding. Accordingly, therefore, an intermittent signal in the nature of an alternating voltage is generated in the secondary winding l6 and the phase of the alternating voltage is directly dependent upon the relative positions of the primary winding and the secondary winding and the frequency of the alternating voltage is directly dependent upon the rate of relative movement of the primary and secondary windings.

Referring to Fig. 2, a receiver ll of Fig. 2 includes a, three phase primary winding having windings 28, 22 and 23 connected in delta and to a three phase alternating voltage source 24. The receiver H also includes a single phase secondary winding 25 inductively coupled to the primary winding. Either the primary winding or the secondary winding 25 may be carried by a rotor 25 so that relative movement between the primary winding and the secondary winding is provided. The rotor 26 may be mechanically connected as at 21 to a device 28 to be moved and positioned.

The primary winding provides a rotating field and when an alternating voltage is applied to the secondary winding 25, the primary and secondary windings are relatively moved to a position depending upon the character of the-alternating voltage applied to the secondary 25. For every phase displacement in the applied alternating voltage the rotor 26 assumes a predetermined positlon and upon a change in frequency of the applied alternating voltage the rotor 26 is caused to move and the speed of movement is proportional to the change in frequency of the applied alternating voltage. Accordingly when an alternating voltage is applied to the secondary winding 25, the rotor 26 assumes positions corresponding to the phase displacement of the alternating voltage and is moved upon a change in frequency of the applied voltage and the rate of movement is dependent upon the frequency value.

Resistances 29 are preferably included in the connections between the primary winding and the three phase alternating voltage source. The resistances 2e are high in value with respect to the impedance of the primary winding and are utilized to prevent distortion of the primary rotary field by reactions from the secondary winding. A power amplifier 32 may have its output connected across the receiver secondary 25. Power for the amplifier 32 is supplied from a suitable source, not shown, by wires 34.

A recorder 40 is associated with the transmitter I and it may take the form of a conventional recorder for producing recordings on a record 42 carried by spools 43. The recorder 40 includes a motor for driving at a constant speed the record 42 and the motor is preferably energized though the wires 4! from the three phase alternating voltage source so that the operation of the recorder 40 is synchronized with the operation of the transmitter Ill. The alternating voltage generated in the secondary l6 of the transmitter if! is applied to the recording means in the recorder 40 for producing intermittent recordings on the record 42, with the displacement of the intermittent recordings relative to the phase of the primary voltage, which serves as a reference frequency, and also relative to the motor-driving voltage applied through wires 4! and serving to drive the record body at a predetermined rate relative to frequency of the primary or reference frequency in accordance with the phase of the generated alternating voltage and the frequency of the intermittent recordings corresponding to the frequency of the generated alternating voltage. The record 42 may take the form of a film and the intermittent recordings thereon the form of spots. Other forms of records 42 may be utilized such as the well known wire record having intermittent recordings of varying magnetism therein. Thus, intermittent recordings are recorded on the record 42, the displacement and frequency of which depend upon the position and rate of movement respectively of the movable device l9.

Associated with the receiver H and power amplifier 32 of Fig. 2 is a record reproducer 45 connected to and synchronized with the three phase alternating voltage source 24 by wires 46. The record reproducer 45 may be of conventional de sign for generating a voltage corresponding to the intermittent recordings on the record 62 carried by the spools 43. The record 42 is driven at a constant speed and in synchronism with the three phase alternating voltage source 24 by a suitable motor located in the record reproducer. The alternating voltage thus generated has a phase and frequency directly dependent upon the displacement and frequency of the intermittent recordings on the record 42 relative to the primary and motor-driving voltages at the time of making the recording, and the alternating voltage thus generated is timed by the relation between phase of current in the primary winding 2|, 22, 23 to the positional relation of the record 42 to the reproducer pickup device, accomplished :trolling the light source.

to the motor-driving voltage applied through wires at with the three phase alternating volt= age source 24. This generated alternating voltage is then amplified by the power amplifier 22 and applied to the secondary winding as of the receiver ii whereby the device 23 to be moved and positioned is so moved and positioned in accordance with the frequency and displacement of the intermittent recordings on the record ea. In this manner movement and position of the device it) may be recorded on the record 62 and then the record 62 may be utilized at a later time for moving and positioning the device 28 tojbe moved.

Fig. 3 represents'a modified form'of transmitter for producing intermittent signals having a phase displacement depending upon'the position of a movable device and having a frequency depending upon the rate of movement of the movable device. The signals thus produced may be transmitted directly to a receiverjms illustrated in Fig. l or the signals may be utilized for producing intermittent recordings one. record d2 carried by spools 433. In this arrangement a differential transmission generally designated at 53 may be utilized. The differential transmission Ell may include a bevel gear 5i operated by an input shaft 52 and a bevel gear 53 operated by an input shaft 50. ,A plurality of gears 58 carried by ashaft 55 mesh with the gears 55 and 53 and the shaft 55 is carried by a yoke 5b rotatably mounted on the shaft 56. The yoke carries a bevel gear 55 meshing with a bevel gear 55 carried by an output shaft 5%. The input shaft 52 may be driven at a constant speed by a gear 57 and pinion 58 driven by a constant speed motor 55 supplied with power by means of wires as leading from some source of power not shown. Preferably the motor 59 is a synchronous motor operated from an alternating voltage source. The other input shaft as may be operated by a gear as which in turn is operated by a movable device 62.

The output shaft 56 of the differential transmission 50 may control a recorder 64. The recorder may take the form of a light modulator supplied with electrical energy by means of wires as leading from some source of power not shown, and the record 42 may be driven at a constant speed through the recorder 66 by a shaft 65 connected by a gear 61 and pinion 58 to the constant speed motor es. The light modulator may include a shutter operated by the shaft 56 for interrupting a light beam or it may include a switch operated by the shaft 56 for intermittently con- In this way the recorder 64 is synchronized with the differential transmission at inasmuch as both are driven from the same constant speed motor 59.

The output shaft 55 controls the light modulator to produce intermittent recordings on the film record 42. When the movable device 62 stationary, the frequency of the intermittent recordings will remain constant but the displacement of the intermittent recordings will be directly dependent upon the position of the movable device 62. When the movable device 62 is moved, the frequency of the intermittent recordings is varied and the frequency will be directly dependent upon the rate of movement of the movable device $2. In this way the position and movement of the movable device $2 is recorded on the record 42 in intermittent recordings. The record 42 may then be run through the record reproducer 45 of Fig. 2 so that the original movethrough the phase relation of the recorded signals ment of the movable device 82 may be accurately 8 reproduced by the device to be moved 20 of Fig. 2. Alternatively the output shaft I operating in conjunction with the constant speed shaft 00 of Fig. 3 may be utilized for generating an alternating voltage which may be applied directly to the voltage amplifier 02 of Fig. 1 for simultaneous movement and position reproduction.

In the arrangement of Fig. 4 the same differential transmission 00 and recorder 04 are utilized and, therefore, like reference characters are used for designating like parts. However, in Fig. 4 it is the purpose to provide intermittent recordings on the record 42 in accordance with predetermined calculations rather than in accordance with movements of a movable device. In this connection the input shaft 04 is provided with a suitable crank or other means for rotating the same. The shaft 04 may be provided with screw threads II for reciprocating a table I2 provided with a follower 10. The follower 13 is adapted to cooperate with lines 14 provided on a movable chart II. The chart I0 may be mounted on a drum and rotated at slow speed through gearing I0, 11, I0, 10, 01 and 58 by the motor 00. The-lines I4 are placed on the chart "I! in accordance with predetermined calculations. As the chart I0 is slowly rotated the crank 10 is operated to cause the follower I0 to follow the lines I4, and the rotative motion of the shaft 54 in thus following the lines I4 controls the operation of the recorder 04 so that the intermittent recordings placed on the record 42 correspond in displacement and frequency to the lines I4 on the chart I5 and hence in accordance with the predetermined calculations.

The record 42 produced by the recorder 04 of Fig. 4 may then be run through the record reproducer 45 of Fig. 2 so that the device to be moved" of Fig. 2 may be accurately moved and positioned in accordance with the original calculations utilized in computing the chart I! in Fig. 4.

If it is desired to have the receivers II control and operate heavy loads, a suitable servo mechanism may be controlled thereby. An improved servo mechanism for moving heavy loads under the control of the receiver II is schematically illustrated in Fig. 5. Here the receiver II corresponds to that of Fig. 2, and like reference characters for like parts have been utilized. The servo mechanism may include a self-balancing network generally designated at M, which may take the form of a conventional Selsyn system. The self-balancing network BI may be provided with control means 82 and follow up or rebalancing means 03. The control means may include a Selsyn motor having 120 degree distributed windings 84, 05 and 00, similar to three phase windings, and a single winding 01. One of the windings may be carried by a rotor 80 mechanically connected as at 21 to the rotor 20 of the receiver I I. Movements in the receiver, there fore, cause corresponding movements in the control means 02.

The follow up or rebalancing means 00 may include 120 degree distributed windings 00, 80

- and 0t, and a single winding 02, one of the windings being carried by a rotor 90, which in turn may be mechanically connected as at 04 to a reversible electric motor 00. The reversible motor in addition to operating the rotor 00 of the follow up or rebalancing means 03 also operates the heavy load 08 which is to be positioned and moved. and in addition it my operate a uadrature drag cup or induction generator 01 for producing an alternating voltage which may be of one phase or of opposite phase, depending upon the direction of rotation, and which may have an amplitude depending upon the speed of rotation.

A phaser I00 may be connected to a source of three phase alternating voltage by wires IN and a single phase alternating voltage may be derived therefrom and applied through an isolating transformer I02 to the single phase winding 02 of the Selsyn system forming the self-balancing electrical network. Also, an alternating voltage may be taken from the phaser I00 and applied through an isolating transformer I00 to the alternating voltage induction generator 01.

The winding 01 of the Selsyn system 0| may be connected by wires I00 to a voltage amplifier I00. When the Selsyn system H is in balance no signal is applied to the voltage amplifier I00 by the wires I00. If, however, the control means 02 of the Selsyn system is moved in one direction an alternating voltage signal of one phase is applied to the voltage amplifier I08 and if the control means is moved in the opposite direction an alternating voltage signal of opposite phase is applied to the voltage amplifier I015. The voltage amplifier I00 is provided with a suitable source of electrical power by wires I01. The output of the alternating voltage induction generator 01 is applied to the input of the voltage amplifier I00 by wires I00. The voltage amplifier I06 mixes the signals from the self-balancing electrical network 8i and the voltage generator 91 into a resultant alternating voltage which is amplified by the voltage amplifier I08. The amplified resultant alternating voltage is applied to the input of a power amplifier IIO by wires I09. A single phase alternating current is suplied to the power amplifier IIO by wires III leading from the phaser I00. An alternating voltage of displaced phase is provided by the phaser I00 through wires II2 to the input of the power amplifier I I0.

The reversible electric motor 90 may be a direct current shunt motor having one of the windings therein supplied with unidirectional current of one polarity or opposite polarity through wires I I0 and H4 from the power amplifier I I0 and having the other winding supplied with a direct current of single polarity through wires IIS and H8 from the power amplifier IIO. Thus the power amplifier I I0 controls the direction and speed of operation of the reversible motor 05 under the control of the power amplifier I00 which, in turn, is controlled by the self-balancing electrical network 0i The self-balancing netand the generator 01. work 0| determines the direction and speed of rotation of the reversible motor 00 for rebalancing the electrical network and the generator 01 operates to retard the rotation of the electrical motor 05 as balance in the electrical network 0i is approached, whereby overshooting and hunting around the balance inated.

A portion of the voltage amplifier I 00 is diagrammatically illustrated in Fig. 6. The voltage amplifier I00 includes a pair of vacuum tubes I20 and I2I, each having a plate I22, a suppresser grid I22, a screen grid I24, a control grid I20, a cathode I20 and a heater I21. The screen grid and the suppressor grid are electrically connected in the associated tube circuit in the conventional manner.

The cathodes I20 of the tubes I20 and I2I are connected to ground through a parallel connected miltanoe I and condmm Ill providiul a unitpoint may be entirely elimable grid bias. The plates I22 of the tubes I20 and I2I are connected together and through resistances I3I and I32 to a suitable source of direct current. The signals produced in the plate circuits of the two tubes are thus mixed and are capacity coupled by a condenser I33 to the subsequent amplifying stages in the voltage amplifier which preferably provides a push-pull ampifying action. Sincethe subsequent stages are conventional in the art. a further description thereof is not considered necessary.

The output from the voltage amplifier is provided with a transformer I36 having a center tapped primary I36 and a secondary I31 connected to the'output wires I09 leading therefrom. A resistance I38 maybe connected across the secondary I31.

The wires I05 leading from the Selsyn system I arezconnected across a resistance I40 one end of which is connected to ground. An adjustable tap I4I associated with the resistance I40 is connected to the control grid I25 of the tube I20. In like manner the wires I08 leading from the voltage generator 91 are connected across a resistance I42, one end of which is connected to grounds-21in adjustable tap I43 associated with the resistance I42 is connected to the control grid I25 of the tube I2I. 'The alternating voltages from the Selsyn system 8| and from the generator 91 are thereby applied to the control grids of the tubes I20 and I2I respectively and the relative amounts of the alternating voltages thus applied may be regulated by adjustment of the taps MI and I43. The output signals from the tubes I20 and I2I are algebraically added and mixed through the resistance I3I into a resultant alternating voltage which is amplified and applied to the wires I09 leading to the input of the power amplifier H0.

The power amplifier H0 is diagrammatically illustrated in Fig. 7 and includes a transformer I46, a rectifier tube I46 having plates I41 and a cathode I48 for producing a direct current voltage across acondenser I49 in conventional manner. Direct current is then supplied. from the condenser I49 through wires I15 and H6 to one of the windings -of the direct current shuntmotor 95. This direct current is always in the same direction.

The power amplifier IIO also includes a pair of gas discharge tubes I5I and I52 each having a plate I53, 8. suppresser grid I54, a control grid I55, a cathode I56 and a heater I51, the suppresser grids I54 being connected to the cathode I56. The gas .discharge tubes I5I and I52 are reversely connected with the plate I53 of tube I5I connected through an inductance I62 to the oathode I56'- of the other tube I52 and to one of the wires III. The plate I53 of the tube I52 is connected through an inductance I6I to the cathode I56 of the other tube I5I and to the wire II3 leading to one of the windings in the direct current shunt motor 95. The other wire III is connected to the wire II4 leading to the winding in the shunt motor 95. The wires I09 extending from the voltage amplifier I06 are connected to a primary I66 of a transformer I65 having a pair of secondaries I61 and I68 respectively, these secondaries being so wound that the left hand ends thereof are positive at the same time. The wires II2 leading from the phaser I00 are connected with a primary I10 of a transformer I69 having a pair of secondaries HI and I12 which are also wound so that the left ends of the secondaries are positive at the same time.

7 half cycle. Therefore, less current is supplied to The left end of the secondary I12 is connected through a resistance I13 to the control-grid I of the tube I6I and the right end of the secondary "I is connected through a resistance I14 to the control grid I55 of thetube I52. The right end of the secondary I12 is connected to the left end of the secondary I68 and the left end of the secondary I1I is connected to the left end of the secondary I61. The right end of the secondary I68 is connected to the cathode I56 of the tube I5I and the right end of the secondary I61 is connected to the cathode I56 of the tube I52. Theinductances I60 and IGI are utilized for interference reduction purposes.

When no signal is applied to the transformer I65, as when the Selsyn system is in balance and the motor stationary, no alternating voltage is developed in the transformer secondaries I61 and I68. When a signal is applied to the transformer I65, the voltage developed in the secondaries I61 and I68 is either in phasewith or 180 degrees out of phase with the supply voltage applied to the gas discharge tubes I5I and I52, depend ing upon the direction of unbalance of the Selsyn system.

The voltage supplied to the transformer I69 from the phaser I00 produces an alternating voltage in the secondary windings HI and. I12 and this voltage lags the supply voltage to the gas discharge tubes I5I and I52 by almost 180 degrees.

Assume now that no signal is applied to the transformer I from the voltage amplifier Ifil- During the first half cycle the plate voltage of the gas discharge tube I5I is positive and the plate voltage of the gas discharge tube I52 is negative. During the second half cycle the reverse condition is true. At the end of the first half cycle the control grid of the gas discharge tube I5I is driven positive by the voltage induced in the secondary I12 whereby the gas discharge tube I5I fires at the end of the first half cycle. During the second half cycle the plate of the gas discharge tube I52 is positive and at the end of the second half cycle the transformer secondary I1I drives the control grid positive whereby the gas discharge tube I52 fires at the end of the second half cycle. In this way a small pulse of current is supplied through the wire II3 to the winding in the shunt motor during the first half cycle and a small pulse is supplied to the winding through the wire I I4 during the second half cycle; These small pulses being of equal intensity in opposite directions tend to maintain the motor 95 in a nascent condition so that it may be readily rotated in one .direction or the.

other upon the occurrence of signals in the transformer I65.

Assume now that the left ends of the transformer secondaries I61 and I68 of the transformer I65 are positive during the first half cycle as a result of unbalance in one direction of the Selsyn system. This causes a forward shifting of the phase of the voltage applied to the control grid of the gaseous discharge tube I5I to advance the firing point of that tube during the first half cycle so that the gas discharge tube I5I supplies more current to the shunt motor 95 through the wire II3 during the first half cycle. During the second half cycle when the left end of the transformer secondary I65 is negative, the phase of the signal applied to control grid of the gas discharge tube I52 is retarded whereby the gas discharge tube I52 conducts less current during the second 9 the shunt motor 85 through the wire I during the second half cycle.

The current supplied to the shunt motor under these conditions of operation, therefore, has a pronounced unidirectional component in one direction to drive the shunt motor in one direction for the purpose of rebalancing the selsyn system.

When the Selsyn system is unbalanced in the other direction, the opposite mode of operation takes place, namely the gas discharge tube I52 conducts longer during the second half cycle and the gas discharge tube ISI conducts less during the first half cycle. As a result of the current supplied to the shunt motor 95 in one direction or the other depends directly upon the resultant of the extent of unbalance of the Selsyn system and the speed of operation of the reversible motor 05. Since the speed of operation of the motor 95 is dependent upon a Signal which is the result of the unbalance of the electrical network II and the action of the generator 91, the motor 95 is accurately controlled to rebalance the electrical network 8| without overshooting and hunting of the system. At the same time it provides for rapid operation of the motor when the electrical network II is greatly unbalanced but as a balance point is approached during the rebalancing operation, the signal is materially weakened by the balancing action and by the generator 91 for slowing down the motor 95 and preventing coasting of the motor beyond the balance position and hunting of the motor therearound.

While for purposes of illustration several forms of this invention have been disclosed, other forms thereof may become apparent to those skilled in the art and, therefore, this invention is to be limited only by the scope of the appended claims and priorart. k

I claim as my invention:

1. A receiver reproducer consisting of, a three phase primary winding for connection to a three phase alternating voltage source, a single phase secondary winding inductively coupled to the primary winding, one of said windings being freely movable relative to the other, a record controlled single phase voltage generating device arranged for operation by a voltage synchronized with a three phase alternating voltage applied to the primary winding for generating a single phase alternating voltage in response to intermittent recordings on the record with the frequency of the generated voltage corresponding to the frequency of the intermittent recordings and the phase of the generated voltage corresponding to the displacement of the intermittent recordings from such three-phase voltage, and means for applying across the secondary winding a single phase alternating voltage corresponding to the generated voltage of sufficient amplitude moving said freely rotatable winding upon a change of effective relative directions of axes of magnetic fields generated by the respective windings, for relatively positioning the windings in accordance with the phase of the applied alternating voltage relative to that of such an applied polyphase voltage.

2. A transmitter recorder including apparathis for advancing a record at a constant speed, recording means energizable by constant frequency alternating current for placing intermittent recordings on the record, a movable delate the frequency of the intermittent recordings in accordance with the speed of the movable device and the displacement of the intermittent vice for controlling the recording means to regu- 10 recordings from preselected phase relation to alternating current energizing said recording means in accordance with the position of the movable device, a receiver reproducer including, a three phase primary winding for connection to a three phase alternating voltage source, a single phase secondary winding inductively coupled to the primary winding, said windings being relatively movable, a record controlled voltage generating device for operation in synchronism with a three phase alternating voltage source to which the three phase primary winding is connected for generating a single phase alternating voltage in response to intermittent recordings on the recordings on the record with the frequency of the generated voltage corresponding to the frequency of the intermittent recordings and the phase of the generated voltage corresponding to the displacement of the intermittent recordings, and means for applying across the secondary winding a single phase alternating voltage corresponding to the generated voltage for relatively moving the windings upon a change in frequency of the applied alternating voltage and for relatively positioning the windings in accordance with the phase of the applied alternating voltage.

3. A receiver reproducer including, a three phase primary winding for connection to a three phase alternating voltage source, a single phase secondary winding inductively coupled to the priary winding, one of said windings being mounted on a freely movable rotor for relative movement of said windings, a record controlled voltage generating device arranged for operation in synchronism with such a three phase alternating voltage source for generating a single phase alternating voltage in response to intermittent recordings on the record with the frequency of the generated voltage corresponding to the frequency of the intermittent recordings and the phase of the generated voltage relative to such a three-phase voltage corresponding to a position to be produced, means for applying to the secondary winding a single phase alternating voltage corresponding to the generated voltage of suflicient amplitude to move said rotor to such a represented position by interaction of magnetic fields generated by the respective windings upon a change in phase of the applied alternating voltage and for relatively positioning the windings in accordance with the phase of the applied alternating voltage,

4. A transmitter recorder including apparatus for advancing a record at a constant speed, recording means for placing intermittent recordings on the record, means for supplying a constant reference frequency signal, a movable device for controlling the recording means to regulate the frequency of the, intermittent recordings in accordance with the speed of the movable device, and the displacement of the intermittent recordings relative to a reference frequency supplied by said constant reference signal means in accordance with the position of the movable device, a receiver reproducer including apparatus for advancing the record at constant speed, a device to be moved, second means for supplying a constant reference frequency signal, means con trolled by the record for moving the device to be moved at a speed corresponding to the frequency of the intermittent recordings and to a position corresponding to the displacement of the intermittent recordings relative to signals supplied by said second reference frequency means. and a servo mechanism controlled by the device to be moved.

5. In a motion degree and rate and position reproducing system that comprises a transmitter assembly for generating a program of signals representing a program of motion, a recorder for making a record of such signal program, a reproducer for generating from such a record a reproduction of such a signal program, and a repeater assembly for producing the motion program from the reproduced signal program; the improvement consisting in the transmitter assembly comprising a variable transformer including in relatively movable arrangement a polyphase primary winding for energization by an alternating current source and a single phase secondary winding connected to the recorder signal input and inductively coupled to the primary winding, means for driving the recorder in synchronized relation with a voltage energizing said primary winding, the repeater assembly comprising a phase-sensitive motor including in relatively movable arrangement a polyphase primary winding and a single phase secondary winding, said windings being relatively disposed for torque-producing interaction of magnetic fields that they respectively generate upon departure of the relative positions of the windings from a neutral positional relation, determined by phase relation of their respective magnetic fields, means for driving the reproducer in synchronism with a polyphase voltage applied to said repeater assembly primary winding for reproduction of signals from the record in the same phase relation to such voltage as the original signals bear to the polyphase primary voltage of the transmitter assembly during their recording, and means for applying to the secondary windings of the repeater assembly a single phase alternating voltage corresponding to the reproduced signals in phase relation to the polyphase voltage energizing the primary winding of the repeater and of sufiicient amplitude to generate winding-driving .magnetic fields.

6. A motion recording and reproducing system comprising; means for advancing a record at a rate having a constant proportional relation to a reference frequency; a transmitter assembly comprising a primary winding for energization by alternating voltage corresponding in phase and frequency to such a reference frequency, and a single phase secondary winding, said windings being inductively coupled, relatively rotatable and arranged for phase displacement of the secondary voltage relative to such reference frequency in proportion to displacement of the respective windings from a neutral relative positional relation and for frequency variations proportional to rate of variation of such displacement; means energized by said secondary winding for making on said record intermittent recordings corresponding in frequency to the frequency of such secondary voltage and in phase relation to such reference frequency corresponding to the positional relation of the windings to their neutral relative positions; second means for advancing a record body upon which such recordings have been made by the transmitter assembly, at a rate having a constant proportional relation to a second reference frequency; means for producing from recordings upon such record signals of frequency corresponding to that 12 of such recordings and of phase relation to such second reference frequency corresponding to that of the transmitter secondary voltage to the first reference fre uency during recording; and a repeater assembl comprising a primary winding for energization by alternating voltage corresponding in phase and frequency to such second reference frequency, a single phase secondary winding, said windings being inductively 'coupled, relatively rotatable freely and arranged for'torque-producmg interaction of magnetic fields that they respectively produce when displaced from neutral relative position that depends in relative phase of such fields; and means for applying to said secondary winding an intermittent voltage corresponding to signals produced from the record in frequency and in phase relation to such secondary reference frequency. and of amplitude sufficient to relatively move said windings toward their neutral position as determined by such phase relation when they windings are displaced from such neutral position.

7. A repeater assembly including means for advancing a record at a rate having a constant proportional relation to a reference frequency, a device to be moved, a motor including a secondary winding, a primary winding for energization by voltage having a frequency and phase corresponding to those of such a reference frequency, one of said windings being carried by a rotor mechanically connected to said device to be operated and for rotation relative to said other winding, and said windings being arrange for torque-producing interaction of magnetic fields that they respectively generate when in other than neutral relative positions of the efl'ective axes of such fields, means for producing from the record signals corresponding to intermittent recordings of variable frequency, means for applying to said secondary winding an alternating voltage corresponding to the reproduced signals in phase relation to such reference frequency, and of sufiicient amplitude to drive the rotor and the device to be positioned by torque produced by such interaction of magnetic fields upon phase disagreement between such secondary and reference voltages.

8. A motion and position recording and reproducing system according to claim 6, wherein the respective primary windings of said transmitter and repeater assembles comprise threephase windings.

9. A repeater assembly according to claim 7 wherein said motor primary winding is a threephase winding.

. RICHARD P.

REFERENCES CITED The following references are of record in the file of this patent:

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